Spending a large part of the day under direct sunlight (e.g., working in a farm), is known to paradoxically reduce the risk of skin cancer; whereas occasional exposure (e.g., working at a desk job and then sunbathing in Cancun) greatly increases the risk.

Perhaps we're not overthinking it. Maybe there are complex processes that we don't yet understand.

This phenomenon has been well known for almost all of history.

https://en.wikipedia.org/wiki/Mithridatism https://www.ncbi.nlm.nih.gov/books/NBK349158/

This is interesting - do you have a source for this?

You absolutely should not get river or lake water in your sinuses if you can help it. The lake I used to swim in as a kid would regularly get warm enough to have amoeba in it that could cause amoebic meningitis and we were always told to keep our heads above water.

> Netis are part of Ayurvedic medicine in India since long before people dreamed of personal immortality.

Yes. And in that time period, average life expectancy was somewhere in the neighborhood of 30 years. The risk of death from neti pot use was hardly significant compared to all the other health risks anyone living at the time would be exposed to.

The same goes for skin cancer. It's a meaningful risk to us today because we can live long enough for the cumulative damage from solar radiation to be a meaningful cause of mortality.

30 is the mean between infants and 60-year-olds. There has never been a society in which dying at 30 was typical.

Infant mortality was the biggest contributor, but there was also higher mortality across all age groups.

IMO most of 'average life expectancy' can be attributed to human ignorance and savagery. Like the savagery of pouring dyes into rivers until too many people die of bladder cancer, then moving the factories to another continent. Repeatedly. Or the savagery of using scientific knowledge to create nukes ... and use them.

One example of ignorance is knee-jerk, gainsaying, scientism about alternatives to Western medicine. My use of Neti was recommended by a well-trained physician, and it was very beneficial. There was indeed practical wisdom in the world before the rise of materialist rationalism.

Oh yeah... and western medicine couldn't save the lady's ass. I'm sure the bill was VERY healthy though.